How do I do (iii) a b and c?

Use set buikder notation to represent the following set: {, -2, -1, 0}

Ineed to know the answer to this algebra question.

Which must be true in order for the relationship △zyv ~ △xwv to be correct? zy ∥ wx ∠z ≅ ∠y and ∠w ≅ ∠x zv ≅ vy and wv ≅ vx ∠z ≅ ∠x and ∠w ≅ ∠y